docs: def map_return_value(self, return_value):
          """
          Returns the mapped return_value of a processed request. If no return_mapping has been
          defined, the value is returned as is. If return_mapping is a static value, that value
          is returned, ignoring return_value completely.
  
          :param return_value: Value to map.
          :return: Mapped return value.
          """
          if callable(self.return_mapping):
              return self.return_mapping(return_value)
  
          if self.return_mapping is not None:
              return self.return_mapping
  
          return return_value